This invention pertains to the field of oceanographic instrumentation systems. More particularly, this invention pertains to the field of support structure design for sonar systems. By way of further characterization, but without specific limitation thereto, this invention provides for a compact, highly portable instrumentation array support structure which can be quickly expanded for deployment and easily retracted for retrieval, storage, and transport.
The accurate and early detection of underwater acoustic events requires the use of large sonar arrays. The size of the array determines the maximum spatial separation of the individual transducers which, in turn, fixes the range and sensitivity of the sonar array.
In the past, support structures for long range sonar systems comprised discrete elements such as buoys and suspended platforms which were individually deployed. Such structures require long deployment and retrieval times, considerable support resources, and use of scarce shipboard space for transport.
Prior art shows the construction and use of unitary sonar array support structures which are expandable for operational use and retractable for retrieval, transport, and storage. Such structures employ a central support body to which are attached a number of elongated support arms which are pivoted at their ends outwardly from the body and extend radially therefrom during deployment, and are pivoted inwardly to lie against the body for retraction and retrieval of the structure.
The compactness of the prior art devices is limited by the length of the support arms. Since the arms, when retracted, lie against the support bodies, the bodies cannot be shorter than the arms. Since the lengths of the arms determine the radii of the arrays, there is a tradeoff of array size and support body length: large arrays entail non-compact structures; compact structures entail small, less sensitive arrays. In addition, the prior art devices must be lifted out of the water for transport and storage.
Maritime requirements for handleability and mobility demand sonar array structures which are as compact as possible for fast deployment and retrieval and for ease of transport and storage. At the same time, the need for compactness must not put a limit on the size of an expanded array lest range and sensitivity of the system be sacrificed.